NYC90FA171 · Lake LA-4-200
Lake LA-4-200 · Accident: in flight collision with object during initial climb
From an unrecorded airport to LAKE GARFIELD, MA
Event
- NTSB case
- NYC90FA171
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Lake LA-4-200
- Aircraft type
- Lake LA-4
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N8011M
- Operator
- Paul E. Thorn · private individual
- Onboard fatalities
- Unknown
- Route
- From not recordedTo LAKE GARFIELD, MA
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- In flight collision with object
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Ignition system, magneto › Other
- Other maintenance personnel › Maintenance, annual inspection, improper
- Pilot in command › Maintenance, not performed
- Powerplant › Low compression
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
AFTER TAKEOFF THE AIRPLANE CLIMBED TO ABOUT 50 FEET AGL AND THE PLT ATTEMPTED TO ACCELERATE TWICE BY LOWERING THE NOSE, LOSING ALTITUDE EACH TIME. THE AIRPLANE THEN BANKED RIGHT BEFORE FLYING INTO TREES ABOUT 1,500 FEET FROM THE END OF THE RUNWAY. IMPACT OCCURRED IN A RESIDENTIAL BACKYARD. THE PASSENGER ESCAPED BUT WAS UNABLE TO RESCUE THE PILOT BEFORE FIRE CONSUMED THE CABIN. AN ENGINE RUN WAS SUCCESSFUL BUT FAILED TO ATTAIN AIR FLOW AND RPM TEST POINTS. DISASSEMBLY REVEALED CORROSION THROUGHOUT INDICATING THAT THE ENGINE HAD BEEN INACTIVE FOR EXTENDED PERIODS OF TIME. THERE WAS ALSO EVIDENCE OF MULTIPLE WORN COMPONENTS AND METAL CONTAMINATION. COMPRESSION ON CYLINDERS 1-4 WAS 65/80, 75/80, AND 69/80 RESPECTIVELY. LEFT MAGNETO TIMING WAS 24.5 DEGREES BTC VICE THE CORRECT TIMING OF 20 DEGREES BTC. AN ANNUAL INSPECTION WAS PERFORMED ON 4/5/90. THE ENGINE WAS NOT CAPABLE OF PRODUCING RATED POWER DUE TO MECHANICAL INEFFICIENCY AND WEAR LIMITS BEING EXCEEDED.
Probable cause
THE PILOT IN COMMAND'S FAILURE TO PROPERLY MAINTAIN THE ENGINE, THE INADEQUATE ANNUAL MAINTENANCE INSPECTION, LOW COMPRESSION, AND IMPROPER MAGNETO TIMING. A FACTOR WAS THE RESULTANT DETERIORATED CLIMB PERFORMANCE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC90FA171
- Event ID
- 20001212X23780
- Case number
- NYC90FA171
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 956df95169a387b66b6a3e527860fb85a59a4f8558ba3ec8e6d14ba1f469831c; retrieved 2026-09-21T02:26:42.712Z.